US 2009/0027493 A1 discloses a method to automate the surveillance of people entering public spaces and taking action in real-time to prevent an attacker from achieving his target. The method includes the strategic placement of high-resolution video cameras in places that are camouflaged from vision. Cameras would be connected by land lines or wirelessly to a central location that would monitor the films recorded. The routine monitoring would be for the most part automatic and computer-controlled. The computer monitoring would include analysis of people's behavior, facial expression, unusual movement and the like. Suspect noise, words or volume could also alert the computer program to warn the trained personnel to focus in on the events at that site. Where possible, analysis of more intricate factors like the heart beat rate or pupil dilation could be monitored and displayed on a sub-screen.
A problem of the known method is that it does not disclose how to obtain the heart beat rate or pupil dilation and how to synchronize data representative of such factors with the video footage used for analysis of suspicious behavior.